Vibrator



March 1965 M. ISAACSON ETAL VIBRATOR 2 Sheets-Sheet 1 Original Filed May 24, 1960 lo INVENTORjT I- ISAACSON MAX JOSEPH FLATT IZ/T Y r B Z /JZ;

' ATTORNEY March 16, 1965 M. ISAACSON ETAL VIBRATOR 2 Sheets-Sheet 2 CIRCUIT BREAKER INVENTOR. MAX ISAACSON BYJOSEPH FLATT Mfilflf Original Filed May 24, 1960 TRANSFORMER ATTO RNEY United States Patent 3,173,664 VIBRATOR Max Isaacson, 420 W. Nottingham Road, Dayton, Ghio, and Joseph Flatt, Dayton, Ohio; said Flatt assignor to said Isaacson Continuation of application Ser. No. 31,393, May 24, 1960. This application July 1, 1963, Ser. No. 292,819 33 Claims. (Cl. --72) This application is a continuation of our prior application, Serial No. 31,393, filed May 24, 1960, now abandoned.

The present invention relates to a vibrator, and is more particularly concerned with a means for vibrating a body in resonance with a minimum consumption of power.

The invention is more particularly adapted for the materials handling and Working arts. The vibrator may be employed to vibrate a bucket which contains materials to be deburred, or the construction may be employed for vibrating various types of objects such as vibratory tables, screens, molds of various types, chutes, and spouts through which powdered or finely defined material is fed, etc.

In the art of vibratory type finishing, many devices have been known, including electro-magnetically actuated devices for deburring, descaling, cleaning, burnishing and general service refinement. Many of these devices constitute large bulky equipment in which vibrations are transmitted to the floor, thus creating structural problems in the area in which the unit is operated. Also, many of such devices do not completely activate the parts and media so that 100% of the media are vibrated; and further require relatively large power consumption.

It is therefore one object of the invention to provide an electromagnetic means for vibrating a member with minimum power consumption. It is further an object of the invention to provide a vibratory type finishing machine of minimum size and which accomplishes the desired finishing operation in the minimum of time and with a minimum of power consumption. A still further object of the invention is to provide a vibrator machine which can be employed for mixing, pulverizing, deburring, descaling, cleaning and screening, grating stones, or for surface refinement of any sized part. A still further object of the invention is to provide a vibrator machine in which 100% of the media is vibrated, with negligible vibration being transmitted to the base of the machine.

Another object of the invention is to provide a vibrator machine in which the element to be vibrated is so mounted as to employ a substantially fixed pivotal axis. A further object of the invention is to provide a vibrating machine in which the material to be vibrated is caused to move orbitally by imparting substantially angular movement to the vibration chamber. A further object of the invention is to provide a vibrating device in which the vibration chamber is laterally offset with respect to a vartical plane passing through the pivotal axis for said chamber thus causing the load within the chamber to move orbitally. A still further object of the invention is to provide a vibratory machine in which the vibratory chamber experience only angular motion and power means are provided to impart vibratory torques to said vibratory chamber.

These and further objects of the invention will become more readily apparent upon a reading of the description following hereinafter, and upon an examination of the drawings, in which:

FIGURE 1 is a perspective view of one embodiment of the vibration machine of the invention,

3,173,654 Patented Mar. 16, 1965 FIGURE 2 is a side cross-sectional view of a modification of the embodiment of FIGURE 1,

FIGURE 3 is a side view of the embodiment of FIG- URE 1 in a secondary operating position,

FIGURE 4 is a perspective view of the embodiment of FIGURE 1 having a screen mounted to the bucket member,

FIGURE 5 is a partial cross-sectional view of a modification to a portion of the device of FIGURE 1,

FIGURE 6 is a perspective view, similar to FIGURE 1, but of a modification thereof,

FIGURE 7 is a partial cross-sectional view taken along line 7--7 of FIGURE 6,

FIGURE 8 is a perspective view showing a further modification of the device of the invention,

FIGURE 9 is a perspective view showing the screening operation of the device of the invention, and

FIGURE 10 is a partially schematic view illustrating the electrical operating circuit of the vibration device.

In accordance with one embodiment of the invention, material to be treated is subjected to vibratory motion, and in addition, a continual tumbling movement of the parts and media is maintained. The spring-mass system of the apparatus of the invention is so constructed and arranged as to operate at resonance, regardless of the loading in the tub or bucket. A primary feature of the invention is the location of an elastic restraint for the member to be vibrated on one side of the center of mass, and the applied excitation force or forcing function is located on the opposite side from the elastic restraint. In another aspect of the invention, the member to be vibrated is restricted by its elastic mount essentially to vibration in only one degree of freedom, and the forced vibrations are transmitted to the member to be vibrated in a plane parallel to this one degree of freedom of the elastically mounted member to be vibrated.

The device of the invention can be analyzed as es sentially consisting of a spring mounted mass connected by its elastic member to a pivotally mounted yoke mass. If the two masses are unequal, then there may exist two modes of vibration, if a resonant system is to be obtained. In one mode, the yoke would essentially stand still and the bucket would vibrate at resonance; whereas in the other mode, the bucket would essentially stand still, and the yoke would vibrate at resonance. Considering only the mode where the bucket vibrates and the yoke essentially stands still, then the amplitude of vibration of the bucket may be approximated by the relationship:

Q t-a where:

A=amplitude Q distu-rbing torque or forcing function K=the bucket constant, or the torque which will oscillate the bucket one radian (torsional stilfness) f =forcing function frequency (frequency of impacted forces) f =natural frequency of torsional vibration of bucketspring system It is desired that the amplitude of vibration be made the greatest possible, since this amplitude is actually damped due to the absorption of energy by the material within the bucket, and since it is desired to give the greatest possible motion to the parts and media. This can be brought about by operating the device at resonance (where 1) K=torsional stiffness of spring restraint on the side opposite-to the point of application I of the forcing function or applied excitation; or by applying the exciting force at a region-of large displacement in vibration of. the bucket, the maximum amount of energy.

will be imparted to the bucket. This is apparent since if the exciting force were applied right at the nodal section, even if it were at the natural frequency of the system, substantially no movement would be obtained of the bucket. Also, by placing the elasticrestraint on the side opposite the applied excitation, the nodal line is caused to move above the point of pivotation of the yoke, thus increasing the effective torque applied to the bucket, and hence the vibrational energy transmitted to the media Wl't'hllllhfi bucket, and decreasing the amount of energy required to obtain desired motion of particles within the bucket.

These latter statements are further made clearer from a consideration of the relationship:

T=period =weight of bucket V l ==rnovement of inertia about the center of gravity d=distance from the center of gravity to the nodal line by locating the elastic restraint above the center of gravity as above indicated, d increases (which increases the torque on the bucket); and by making the spring sti-ifer, K is increased. By proper tuning, the system will be given 7 a period equal to that normally available from 60 cycle supply so that the system will operate substantially at'resonance and with maximum energy transmitted to the particles within the bucket.

As another consideration, the system is so-constructed and arranged as to have a high moment of inertia. Thus, any increase in the mass of the system (such as might be obtained by adding a large mas-s to the bucket without gible effect upon the natural frequency of the system and changing its moment of inertia), will have an almost neglitherefore not disturb the resonantoperation of the system;

Referring now to FIGURE 1, in which a pr'eferred em flanges 8 and 10 may be suspended above the groundby appropriate shock mountings, such as 12, 14 and 16- (four being generallyemployed). The upper portion of flange 2 is provided with a hearing or journal mount 20, which journals a stub-shaft 22 affixed to a yoke member 30. The

yoke member 30 essentially has the form of a .U-shaped frame, with upstanding legs 24' and 28 and alower bed portion 26, forming a support for an electromagnetic motor (as described more fully hereinafter). It is readily understood that the other upstanding arm28 of the U- shapedyoke is also provided with a' stub-shaft 22 (not shown) which is similarly journaled Within a bearing means (also not shown).

The yoke 30 is thus freely pivotally mounted Within the frameworkl by being journalled within the journal bearings 20, 20. At the upperedge of the yoke arms 24 and 28v there is provided a mounting plate 32 (only one will be described, however it isreadily understood, thatboth 40 as shown in FIGURE 3.

46 being provided with asimilar mounting plate 42 having a series of fastening openings. Interconnectedbetween the plates 42 and 32, and also serving as a supporting and suspending means for the bucket 40 withinthe yoke 30' isthe elastic restraint or springSt). This spring is shown as a substantially I-shaped'beam, however it is to be readily understood that any type of spring may be employed and the spring-mass system can be accordingly designed to attain the desired degree of resonance. may be lined with a rubber or other resilient surface and provided with a peripheral mounting flange 42. The lower portion ofthe bucket 40 may also be provided with reinforcing ribs 44 and 46 to increase the rigidity of the member. l

The lower portion of the bucketAt) is provided with an armature member 52, which may be composed of a-single slab of electronagnetic material, ormay be made of a laminated member. The armature 52 may be appropriately fastened to the bucket in any desired manner, however it is preferred that welding be not employed and that a multi-plate or laminated member-be used. The armature57 is placed between a pair of coils 60, 60A (only one being shown), the coils being adjustably mounted to the base 26 of the yoke 30. The coils may be mounted on an I-shaped flange member. 62,, to facilitate the assembly. The adjustable mounting may'simply consist of an elongated opening 64 in :the coil holding member 66, through which a fasteningmeans 68 is passed to assemble the holder 66' to the base "62. Four of such fasteners 68 would be employed where two coils are employed. R is to be readily understood that only one coil may be employed, although it is preferred that a pair of coils be. employed;

" matic or hydraulic. cylinder 76' supplied by appropriate connections at 78 and 80 :to a source of fluid under pressure; By appropriate fluid valvin'g controls(not,sh'own), the arm or plunger 74 may be withdrawn from or drawn into the cylinder 76, and by its attachment to the, crank arm 70,.cause, rotating or tilting motion of the bucket This tilting of the bucket 40 maybe desired as shown in FIGURE 3, where dumping of the contents of. the bucket is programmed to remove either the material being worked :upon or the stones from within the bucket. Also the cylinder 76 may be employedto rotate the bucketv into the position shown in FIGURE 3 where it is desired to flush any loose powdery material from the bucket 40 without removing either the stones or material that is being worked upon.

Assh'ownin FIGURE 4, an appropriate screen may be clamped by an appropriate clamping means 102 to thefiange 42 of the bucket 40. This screen 100 is provided with a fine mesh 104 so that only powdery materials can pass therethrough, the screenalso is provided with cleats 106 and 108 to enclaspthe opposite portion of the fiange '42 to the screen whenthe'clamp 102 is closed.

' Formed on a portion of the screen 100 is a nozzle or hose connection 110 to permit attachmentzto a coupling 112 of sults that when the FIGURE 3 position is reached, the

loose powdery materialwill freely flow out of the buck- 'Although the circuitry ofthe wel'e'ctromagnet motor of theinvention is described in a separately filed application,

sides of the yoke are similarly constructed). This inounting plate 32 is provided with a series of holes toreceive the elastic restraining means. A tub or bucket 40 is located within the U-shaped yoke 30,each side of the bucket FIGURE 10 shows one possible actuating circuit. The

circuit will now be described in connection with the operation of the embodiment of FIGURE 1.

Asshown in FIGURE 10, current supply to the coils 60, 60A isiobtained from a'power source 116, and may be an AC. supply. This supply is conducted via leads 122, 124 (with a circuit breaker 118. interposed in line 122) to a timing 'device 120. This timing device may be The bucket 40' one which is pre-programed to provide for certain desired automatic operations of the vibrator, or else may be one which can be reset and manually actuated to provide different cycles for the vibrator of the invention. Power is then conducted from the timer through leads 126 and 128 to a transformer 136, which may either be a stepdown or step-up transformer, depending upon the size of the coils 60, 60A, and the requirements of the particular unit. The output of transformer 136 is an AC. output, and half-wave rectifiers 140 and 142 are provided in line 132, and are so oriented as to supply opposite polarity D.C. to the two coils 60, 60A, via leads 13% and 138, respectively. The circuit thus provides pulsating DC. to the coils 60, 60A, and upon each half-wave pulse the armature 52 is alternately attracted to the coil do, and then attracted to the coil 60A; the magnetic pulses occurring alternately with the frequency of the supply current, which results in an oscillation of the armature 52 at the input A.C. frequency. The stiffness of the spring member 56 is so chosen that it will cause the bucket to oscillate substantially in resonance, thereby reducing and minimizing the power requirements of the unit.

In the unit as just described, the particles will flow as indicated in FIGURE 1 so that a tumbling motion (with the high portion of the flow almost reaching the upper rim of the bucket 40 as viewed in FIGURE 1) causes the particles to flow counterclockwise as viewed from the right, in perspective. Where it is desiredto obtain counter rotating flow of particles, or else where a large workpiece is to be handled by the device, and both sides of it are desired to be subjected to the finishing operation; the modification of FIGURE 2 can be employed. In this modification only the shape of the bucket 40A has been changed so that the bottom of the bucket is provided with a humped portion 150. Also, the suspending spring 50A is placed substantially centrally of the bucket 40A as viewed in the side view, so that the point of connection of the spring lies in the vertical plane containing the center of mass of the bucket. With this arrangement, two counter rotating flows 152 and 154 will be obtained. Thus if desired, a lar e bulky workpiece can be placed substantially centrally of the bucket and immersed in the flow of treating media. Also, since the coils tit) and 69A are mounted on the I-beam standards 62 of the bed 26 of the U-frame 3b, the coils can be positioned by proper adjustment of the fasteners 68 within the slots 64, so that the coils can be positioned at varying distances from the armature 52. Thereby, variations in the air gap and in the restoring and actuating forces created by the coils on the armature can be attained.

Where it is desired to continuously rotate the bucket while tumbling, with a lid being clamped to the flange 42 of the bucket to prevent loss of parts, the modification shown in FIGURE 5 may be employed. In this arrangement, the unit is constructed substantially identical to that shown in FIGURE 1, with the exception that the upstanding arm 24 of the yoke has an elongated stub shaft 222 which is provided at its outer end with a series of impeller vanes 224, which cooperate with driving vanes 226 appropriately mounted within a turbine housing 228. Appropriate inlet and outlet openings 230 and 232 are provided for the turbine 228. This turbine construction is shown as conventional, and is only indicative of the concept of providing a means for rotating the bucket 4t) where such motion is desired. Thus, an electric motor drive could also be employed. In this modification, the air cylinder '76 is replaced by the turbine 228. The shaft 222 is free to rotate Within the journal 22% so that the yoke, spring and bucket 40 may rotate as a unit about the axis of the shaft 222. While this is occurring, the bucket may be continuously vibrated, providing that the necessary slip-ring connections (not shown) are made, to permit conduction of current to the coils 60, 60A.

The bucket-yoke-spring system shown in the drawings may be considered as a system having two natural modes of motion each with its corresponding natural frequency. Thus, if the frequency of the forcing function is equal to the natural frequency of the bucket-spring system, the bucket will oscillate at its maximum amplitude and the yoke will remain substantially motionless. Conversely, if the frequency of the forcing function is made substantially equal to the natural frequency of the yoke-spring system, the yoke will oscillate at its maximum amplitude and the bucket will remain substantially motionless. It is further apparent that although as shown in FIGURE 1, the electromagnetic motor is mounted so as to apply forces directly to the bucket; the motor could be mounted so as to apply forces directly to the yoke, or a motor could be mounted directly to the bucket, or else a motor having an unbalanced mass coupled by a flexible coupling to the bucket could be mounted on the yoke member. In this manner, any desired predetermined motion of the particles within the bucket can be attained.

Where it is desired to superimpose on the main train of vibrations transmitted to the parts within the bucket, a higher frequency small amplitude vibration (i.e., such as may be employed where a fine degree of polishing of the parts is desired), an additional means to apply forced vibrations to the yoke at or near the natural frequency of the bucket, may be employed. Such an arrangement is shown in FIGURES 6 and 7. In these figures, only those elements added to the device shown in FIGURE 1 are identified by reference numerals. Thus, it is seen that a mounting plate 200 is positioned below the bottom portion 26 of the yoke 30, the plate 200 being yieldingly affixed to the yoke by a series of bolts 292 (there being four such bolts employed). As shown more clearly in FIGURE 7, each bolt 202 is immovably amxed to the bottom portion 26 of yoke 30 by a headed end 204 and a nut 206. A pair of springs 208 and 210 are placed, one above and one below the plate 200. The lower end of the bolt is provided with a pair of nuts 212 to capture the lower spring 219 below the plate 200. The nut 266 captures the spring 208 between the upper portion of plate 26%) and the yoke 30. Thus, the plate 200 is yieldingly guided up and down to permit freedom of motion of the plate 2% in a vertical direction, while restricting independent motion of the plate 200 in any other direction with respect to the yoke 30. An appropriate motor means 220, having an output shaft 222 with an unbalanced weight of appropriate mass 224 mounted thereon, is affixed by bolts 226 to the mounting plate 200, substantially centrally thereof. Upon actuation of the motor 220 and revolution of the unbalanced mass 224, oscillatory forces will be imparted to the yoke through the bolt mounts described in the direction of freedom of freedom of motion of the bucket, whereas any vertical forces will be substantially canceled out by the spring mountings 298, 210. Thus, a means is provided for transmitting vibrations to the yoke 30 by means of the unbalanced mass 224. The motor 220 can be rotated at any desired speed, thus changing the frequency of the impressed forces. If the frequency of the impressed forces caused by rotating mass 228 is equal to, or substantially equal to, the natural frequency of the bucket, additional vibrations will be transmitted to the material within the bucket and superimposed upon the main vibrations created by the coils and dfiA. There would thus be obtained a large response of the bucket in its natural frequency or fundamental mode, with superimposed fine vibrations which may be at the natural frequency of the bucket, of the yoke, or any intervening frequency. It is readily understood that the two massspring coupled systems just described in connection with FIGURES 6 and 7 is roughly analogous to a dynamic vibration absorber, and that accordingly many variations in tuning and/or dampening can be made to give any desired motion of the particles within the bucket that is obtainable with such a system.

savanna a As indicated in FIGURE 8, various. spring arrangements may be employed other than the I-beam section shown previously in the drawings.v Thus, a tubular 1'6". 7

entrant type spring 300 may be connected at one of its flanged ends, 302 to the bucket 40, and at the other of its flanged ends 304 to the upstanding leg 24 of a frame 310. The spring 300 is shown as being positioned on the right side of a vertical plane including the center of massof the bucket 40, and hence the flow of partswould be clockwise as viewed from the right in FIGURE 8,: with the high portion of flow on the left side of the bucket. V

ings 400- (see FIGURE 9-) is employed. This screen 460 410 will be separated from the media within the bucket as shown or else the stones will be separated, into the container 420; depending upon their relative sizes;

It will be readily understood that many modifications may be made of features of construction in the'devicedescribed while still coming within the scope of the invention as set forth in the appended claims.

What we claim is: 1'. A vibratory device comprising, incombination; a

of. regardless ofthe magnitude. of the load; said. mounting further including meansyieldingly restraining'relative movement between said vibratile element and' support frame; and motive-power means mounted upon said device so as to impart forced vibrations to said vibratile element.

Y 5. The vibratory device ofclaimA including a substantially rigid yoke interposed betweenfsaid frame and vi- 7 bratile element, said yoke being pivotally mounted within saidframe and said vibratile element being yieldingly suspended from' said yoke. '6. The vibratory device of claim 4 wherein said yieldingly restraining means is arranged to limit motion of said vibratile element substantially to angular displacement about said pivotal axis. 7 P

7. A vibratory device of claim 5 wherein said yielding suspension is constructed so as to limit motion of said vibratile element'substantiallyto angular displacement about said pivotal axis- 8. A vibratory device comprising in combination: a

l vibratile element adapted to carry loads, to. be vibrated vibratileelement; a substantially rigid support frame;

means angularly displaceably interconnecting said vibratile element to said support frame to produce an effective substantially fixed pivotal axis above the center ofmass of said vibratile element; means yieldingly restraining relative movement between said vibratile element and support; said vibratile element and yieldingly restraining means forming a vibrating system having anatural frequency of vibration; and motive power means mounted so, as to impart forced vibrations to said vibratile element,"

the frequency of said forced vibrations being substantially equal to the natural frequency of said vibrating system.

2.. The vibratory device of claim 1 including a second motive power means intercoupled to said. vibratile element for imparting forced vibrations thereto. at a frequency other than the natural frequency of said vibrating system. 3. A. vibratory device comprising, in combination: a vibratile element; a substantially rigid support frame; means angularly displaccablyinterconnecting said vibratile element to said support frame to produce" an effective substantially fixed pivotal axis above the center of mass of said vibratile element; meansyieldingly restraining-relative movement between: said vibratile element and support; said vibratile element and yieldingly restraining.

means forming a vibrating system having a natural frequency of vibration; a substantially rigid yoke pivotally mounted between said support frame andvibratile element, motive power means mounted so as to impart forced vibrations to said vibratile. element, the frequency ofsaid forced vibrations being substantially equal to the natural frequency of said vibrating system,.said yoke andyieldingly restraining means. forming a second vibrating sys tern having its own frequency of vibration, and. a second motive power means intercoupled to said vibratile element for imparting forced vibrations thereto at the nat 1 ural frequency of said second vibrating system. 1

4. A vibratory device comprising, in combinationr'a.

' therewithin, said mounting being such that a fixed effective pivotal axis is established for said vibratile element and is substantially located above the center of gravity there so that the load moves orbitally; a. substantially rigid support frame; said vibratilev element being mounted within said' frame 'for angular displacement therewithin; said mounting being such asto establish a pivotal axis for said vibratile element located above the center of gravity of the element such that the plane including said pivotal axis and the center of gravity of the vibratile elementextends in a direction other than vertical; said mounting means including means yieldingly restraining relative movement between said vibratile element and support frame; and motive power means mountedupon said device so as to impart forced vibrations to said vibratile element, whereby oscillatory motion, imparted to. the vibratile element results in orbital motion of the load contained in said vibratile element."

9. The. vibratory device of claim 8 including a substantially rigid yoke interposed between said frame and vibratile element, said yokebeing pivotally mounted withinsaid frame and said vibratile element being yieldingly suspended from said yoke.

l0. The-vibratory deviceof claim 8 wherein said yieldingly restraining means is arranged tolimit motion of said vibratile element substantially to angular displacement about said pivotal axis,

7 11. The vibratory device of claim 9 wherein. said yielding suspension is constructed so as to limit motion of said vibratile. element substantially to angular displacement about the pivotal axis ofsaid vibratile element.

12. A. vibratory device comprising in combination: a vibratileelement adapted to carry loads to bevibrated so that theload moves orbitally; a substantially rigid support frame; said vibratile element being mounted Within said frame for angular displacement therewithin; said mounting being such as to establish a pivotal axis for .said vibratile elem'ent suchthat the plane including said pivotal axis and the center of gravity of the vibratile element extends in a direction other than vertical; said pivotal axis being substanatially fixed and located'above the center or gravity of said vibratile elementregardless of suspended from said yoke.

. The vibratory device of clainr 12 wherein said yieldingly restraining means is arranged to limit motion 9 of said vibratile element substantially to angular displacement about said pivotal axis.

15. The vibratory device of claim 13 wherein said yielding suspension is constructed so as to limit motion of said vibratile element substantially to angular displacement about said pivotal axis.

16. A vibratory device comprising, in combination: a vibratile element adapted to carry loads of various magnitudes to be vibrated so that the load moves orbitally; a substantially rigid support frame; said vibratile element being mounted within said frame for angular displace ment therewithin, said mounting being such that afixed effective pivotal axis is established for said vibratile element and is substantially located above the center of gravity thereof regardless of the magnitude of the load; said mounting further including means yieldingly restraining relative movement between said vibratile element and support frame; and motive power means mounted upon said device so as to impart vibratory forces to said vibratile element, the point of application of said vibratory forces being contained in the plane including the effective pivotal axis and the center of gravity of said vibratile element, said forces being applied in a direction substantially perpendicular to said plane whereby the linear vibratory reactions of the vibratile element are minimized.

17. The vibratory device of claim 16 including a substantially rigid yoke interposed between said frame and vibratile element, said yoke being pivotally mounted .within said frame and said vibratile element being yieldingly suspended from said yoke.

18. The vibratory device of claim 16 wherein said yieldingly restraining means is arranged to limit motion of said vibratile element substantially to angular displacement about said pivotal axis.

19. The vibratory device of claim 17 wherein said yielding suspension is constructed so as to limit motion of said vibratile element substantially to angular displacement about said pivotal axis.

20. A vibrating device comprising, in combination: a substantially rigid support frame; an element having a load carrying chamber to be vibrated; means for mounting said element to be supported by said frame for angular displacement of said element therewithin relative to said frame, said mounting means including a yielding means on each side of said element coupling same to said frame and forming an effective pivotal axis for said element; said chamber being laterally offset with respect to the vertical plane passing through said pivotal axis and said chamber extending to a greater distance on one side of said plane than on the other, said chamber further having a load supporting surface curved substantially in the direction of the motion of the load in said chamber; and power means associated with said element for imparting forced vibrations thereto.

21. The vibrating device of claim 20 wherein the said pivotal axis lies above the center of gravity of the element.

22. The vibrating device of claim 20 wherein each yielding means comprises a spring beam connecting one of the upstanding sides of said frame to a side of the element, said yielding means serving to suspend said element from said frame and restrict the motion of said element to substantially one degree of freedom.

23. The vibrating device of claim 20 wherein said motive power means comprises a magnetizable armature mounted on the outer surface of said element, and coil means disposed on either side of said armature, whereby upon power being supplied alternately to each coil means the armature is intermittently attracted to said coil means and thereby said element is caused to oscillate about said pivotal axis.

24. A vibratory device comprising, in combination: a substantially rigid support frame; a substantially rigid yoke pivotally mounted within said frame; an element mounted for angular displacement within said yoke relative to said yoke; and electromotive power means including an armature and a coil means on each side of the armature, said armature being mounted upon said element and the coil means being mounted upon said yoke, whereby the reactant forces experienced by said coil means are substantially absorbed by the inertia of the yoke.

25. The vibratory device of claim 24 wherein said pivotal mounting includes a yielding means on each side of said element and said frame has spaced apart upstanding sides, the yielding means being arranged to couple the element to the sides of the frame and forming an effective pivotal axis for the said element located above the center of gravity of the element.

26. A vibrating device comprising, in combination: a substantially rigid support frame; an element having a load carrying chamber to be vibrated; means for mounting said element to said frame for angular displacement relative to said frame, said mounting means including a yielding means coupling said element to said frame and forming an effective pivotal axis for said element; said chamber being laterally offset with respect to the vertical plane passing through said pivotal axis and said chamber extending to a greater distance on one side of said plane than on the other, said chamber further having a load supporting surface curved substantially in the direction of the motion of the load in said chamber, and power means associated with said element for imparting forced vibrations thereto.

27. The device of claim 26 wherein the pivotal axis is so located with respect to the element so as to produce predominantly angular motion of said element about said pivotal axis.

28. A vibratory device comprising in combination:

a substantially rigid support frame;

a substantially rigid yoke element pivotally mounted within said frame;

a load carrying chamber element for angular displacement within said yoke relative to said yoke;

and electromotive power means including an armature and a coil means on each side of the armature, said armature being mounted upon one of said elements and the coil means being mounted upon the other of said elements, whereby the reactant forces experienced by said power means are substantially absorbed by the inertia of the yoke.

29. The vibratory device of claim 28 wherein said pivotal mounting includes a yielding means coupling said load carrying chamber element to the frame and forming an effective pivotal axis for the said element located above the center of gravity of the element.

30. A vibratory device comprising, in combination:

a vibratile element adapted to carry loads of various magnitudes to be vibrated;

a substantially rigid support frame;

said vibratile element being supported by said frame for angular displacement relative thereto, said element being supported by means yieldingly restraining relative movement between said vibratile element and support frame, said support being such that a fixed effective pivotal axis is established for said vibratile element, and said vibratile element being so related to the pivotal axis as to provide differential accelerations for different portions of said load at different locations within said element whereby orbital movement of said load will be attained;

and motive power means mounted upon said device and arranged so as to impart vibratory torques to said vibratory element.

31. The vibratory device of claim 30 including a substantially rigid yoke pivotally supported by said frame;

said vibratile element being mounted for angular displacement within said yoke relative to said yoke,

and a second motive power means arranged to impart revolving motion of both said yoke and said vibratile 32. An, electromotive powered device comprising, in"

combination I a pair of stationary electromagnets; an oscillatable load containing member;

pivot means mounting said loadcontaining member for restrained angular movement about'an effective fixed axis; said load containing member having armature means disposed in adjacent spaced-relation to each electromagnet so as to be within the electromagnetic fields thereof when said electromagnets are energized;

resilient means so arranged with respect to said load containing member asto normally maintain said load containing member ina neutral position when said electromagnets are unenergized and said resilient means being at such timesunstressed, but also be- 1 allow said electromagnets to be alternately energized by said A.C. for moving said load containing member away from said neutral position and'for substantially sinusoidally oscillating said load'containing member in synchronousrelation to said AC. 33. A vibrating device comprising, in combination: a

substantially rigid support frame; an element to be vibratedhaving' aload carrying chamber fined with respect to said element; means for mounting said element to said frame for angular: displacement ofsaidaelement and chamber relative to said frame, said mounting means including' a yielding means coupling said element to said frame and forming an effective pivotal axis for said element; said chamber'being laterally offset with'respect to the vertical plane passing through'said pivotal axis, said" chamberffurthefr having a load supporting surface curved substantially, in the direction of the motion of said charm ber, a'nd'p'ower means associated 'with 'said element for imparting forced vibrations thereto.

References Cited by the tElraminer i t UN E STAT rATE n6. 23,065 12/43v E1145 68--21OX 487,870 12/ 92 Richter 259 7s 646,994 4/00 Janney 259 75 "1,672,807 6/28. Etzel. 7

2,187,717 1/40 Weyandt.- 2,468,515 4/49 Robinson 259-1 2,493,441 .1/s0 Carr, .2s-9 75- 2,774,493 12/56 Winter 214 .64.2x 2,973, 0 3/61 Brandt s1-7 FOREIGN PATENTS 427,305 16/29; Germany- CHARLES WIL'LM-UTH, Primary Examiner. 

30. A VIBRATORY DEVICE COMPRISING, IN COMBINATION: A VIBRATILE ELEMENT ADAPTED TO CARRY LOADS OF VARIOUS MAGNITUDES TO BE VIBRATED; A SUBSTANTIALLY RIGID SUPPORT FRAME; SAID VIBRATILE ELEMENT BEING SUPPORTED BY SAID FRAME FOR ANGULAR DISPLACEMENT RELATIVE THERETO, SAID ELEMENT BEING SUPPORTED BY MEANS YIELDINGLY RESTRAINING RELATIVE MOVEMENT BETWEEN SAID VIBRATILE ELEMENT AND SUPPORT FRAME, SAID SUPPORT BEING SUCH THAT A FIXED EFFECTIVE PIVOTAL AXIS IS ESTABLISHED FOR SAID VIBRATILE ELEMENT, AND SAID VIBRATILE ELEMENT BEING SO RELATED TO THE PIVOTAL AXIS AS TO PROVIDE DIFFERENTIAL ACCELERATIONS FOR DIFFERENT PORTIONS OF SAID LOAD AT DIFFERENT LOCATIONS WITHIN SAID ELEMENT WHEREBY ORBITAL MOVEMENT OF SAID LOAD WILL BE ATTAINED; AND MOTIVE POWER MEANS MOUNTED UPON SAID DEVICE AND ARRANGED SO AS TO IMPART VIBRATORY TORQUES TO SAID VIBRATORY ELEMENT. 